Korrektor / Duden Rechtschreibung 8.0.0.2
Crash happens on my DELL Latitude E6430 with Windows 7 64bit SP2 as well as on my Samsung NC10 with Windows XP 32bit SP3.
Duden works fine on both Systems with LibreOffice 4.0.4 as long, as the instructions of Duden support are followed: "Duden Korrektor will work with this version only if you put the stlport_vc7145.dll from 3.6.x installation somewhere in your %PATH%.Note that you will have to have also MSVCR90.DLL installed on your system."
This however does not seem to apply to 4.1. Crash seems to have to do with a MSVCR90.DLL
Can#T say wether it's a duplicate of fdo#58177 because LO doesn't even start...

#libreoffice-dev on FreeNode:
> <sberg> Fridrich, our official LO 4.1 Windows builds use msvcr100.dll now, right? I wonder whether that's causing the trouble in fdo#66050, when the Duden extension needs stlport_vc7145.dll, and copying that over from an old inst needs msvcr90.dll, and needing two different msvcr versions in one process makes it all break down
> <Fridrich> sberg: it could eventually, yes, but I really have no solution there
> <Fridrich> sberg: the solution would be that they simply rebuild that whole extension using as linker libraries the static multithreaded ones
> <sberg> Fridrich, thx; not looking for a solution, just wanting to label the issue correctly ;) (it's currently marked duplicate of a Mac-only issue, which is apparently wrong)

Copying stlport_vc7145.dll was just a workaround that worked with LO-4.0. IMHO, the correct solution would be that Duden corrector authors provide a clean build that would work with LibreOffice out of box.
I understand that it is very annoying for affected people. But I am not sure if we could do something about this from the LibreOffice side. Such bugs could not block the release with many other useful fixes and improvements => lowering the severity a bit.

Well; that's sad - if Duden won't fix it their extension won't work with any modern OpenOffice derivative; on the plus side, perhaps that will stimulate people to help invest in improving Free Software solutions for German grammar / correction.

When I updated LO from 4.0.x to 4.1.0 today (on Windows), Writer and "Chooser" would crash on launch, something about "MSVC100.dll". A little googling revealed this to be Duden Korrektor's fault (again).
I realise that closed source extensions with uncooperative developers are a pain, I just wanted you to know that a workaround from the LO side would be much appreciated. Sadly, Duden Korrektor is so far ahead of the competition (libre or not), that someone who works a lot with written German can hardly do without it. For now I've just downgraded to 3.6.x (4.0 was very buggy here, anyway), but that's only a stop gap measure, obviously.

(In reply to comment #8)
> I realise that closed source extensions with uncooperative developers are a
> pain, I just wanted you to know that a workaround from the LO side would be
> much appreciated. Sadly, Duden Korrektor is so far ahead of the competition
> (libre or not), that someone who works a lot with written German can hardly
> do without it. For now I've just downgraded to 3.6.x (4.0 was very buggy
> here, anyway), but that's only a stop gap measure, obviously.
+1
I totally agree with that!

(In reply to comment #9)
> Using this dll
>
> http://dev-builds.libreoffice.org/stlport_vc7145.dll
>
> instead of the one from the 3.x series improved things for me.
I just tried that one with LO 4.1.0.1 under Windows 7 Enterprise 32-bit SP1.
It doesn't make any difference here. LO still crashes after installing "Die Duden-Rechtschreibprüfung 9.0 für OpenOffice und LibreOffice".
I downgrade to LO 4.0.4.

Closing Duden Korrektor bugs as NOTOURBUG. This extension is broken beyond repair and Duden is not willing to fix it. The plug in is not OpenSource so nothing the community could do about it.
NOTOURBUG is the correct state. Thanks for understanding. And feel free to give the BI-Media group a phone call and address this problem if you like: http://www.bi-media.de/
*** This bug has been marked as a duplicate of bug 59107 ***